An analytical model to predict the temperature in subway-tunnels by coupling thermal mass and ventilation

There is an increasing incidence of overheating in subway tunnels recent years especially old subways without air-conditioning e.g., London Underground. still lack a clear understanding how tunnel-air temperature determined by complex thermal processes tunnels. In this study, mathematical model that describes the deeply buried was developed. Analytical solution derived separating into time-averaged component and periodic component. The results show will approach steady state as time tends to infinity, which has positive linear relation with internal heat-source average ambient temperature. Active cooling or heat-recovery systems could soon become necessity due both global warming heat generation. Compared outdoor air, amplitude shows significant reduction day period but not year period. surrounding soil keep changing for thousands years. This study offers new physical insight analyse mitigate